An operation apparatus able to continuously perform processing involving computations differing according to the input conditions, able to keep down useless processing when for example the processing may be interrupted in the middle if certain conditions are satisfied, and able to achieve an improvement of transfer efficiency of course and also able to keep down any increase of the system cost and able to reduce the processing time and power consumption, including an address generator for generating first source data and outputting it together with a control signal, an address generator for generating second source data and outputting it together with control signals, and an operation element for performing predetermined operation with respect to the first source data from the first generator and the second source data by the second generator while switching the type of operation in accordance with a control signal and having registers for temporarily holding operation results, wherein reading and writing of held data of registers are controlled according to control signals.